The use of multiple processor cores in a processing system facilitates efficient computation and efficient use of shared resources. However, due to manufacturing defect, one or more of the processor cores may be permanently deactivated. Conventional techniques for deactivating a processor core typically involve initializing all of the processing cores of a system during a start up sequence, and then applying a boot (or start-up) voltage to the deactivated processor core while a normal operating voltage is applied to the remaining activated processor cores. A boot voltage is sufficient to permit a processor core to perform basic operations, such as basic input/output system (BIOS) initialization, and execute at least a subset of instruction types. However, while the boot voltage typically is lower than the normal operating voltage and therefore can decrease power consumed by a deactivated processor core, the boot voltage typically causes significant leakage current at the transistors and other circuit components of the deactivated processor core, thereby resulting in continuing power consumption by the processor core even though it has been deactivated. Accordingly, an improved technique for deactivating processor cores would be advantageous.
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